Behind-the-scenes tour of ALMA, the world's greatest radio telescope

Coming off the heels of the greatest night of observing our Astronomy magazine tour group had ever experienced, we were in for another treat on Monday, May 26. Our Chilean adventurers, more than 30 strong, were in heaven as they became the first large tour group of astronomy enthusiasts to visit the Atacama Large Millimeter/submillimeter Array (ALMA), the world’s most sophisticated radio telescope.

A joint European/North American/East Asian project, of course with Chile as a partner and the host country, ALMA began construction in 2003 and has essentially just finished it, although work will go on to optimize the telescope and its operations for some time. The telescope was formally inaugurated in March 2013. Its sixty-six 12-meter and 7-meter radio telescopes, located high in the Chajnantor Plateau of the Atacama Desert at 16,597 feet (5,059 meters), operate together in a multitude of configurations, connected together as one giant interferometer. Thus, the telescope’s power is far beyond that of previous radio telescopes, and it is one of the most ambitious scientific instrument projects in history.

We visited ALMA’s Operations Support Facility, just shy of 10,000 feet (3,048m)in altitude, where the control rooms are located, as well as several antennae, the huge antenna-moving trucks, workshops, clean rooms, staff officers, meeting rooms, and much more. It is the heart of the ALMA complex. Our host was Andreas Lundgren, deputy lead program manager, who delivered a sensational hour-long overview of the instrument and its projects. We learned about an array of research underway that touch on star birth, molecular gas clouds, distant galaxies, starburst galaxies, gravitational lensing, the nearby NGC 1097, the interstellar medium, and much more.

We then had the opportunity to explore the grounds, including the examples of antennae standing near the operations building, the huge antenna-moving trucks. We also heard about future science plans for the facility. It was a spectacular visit and one that will stay in our memories for a very long time.

The group then had the chance to visit the Atacama Salt Flats to see wildlife such as flamingoes, various other birds, briny shrimp, and lizards, as well as marvel at the incredible arrays of salt and realize this is the world’s leading source of lithium. It was another red-letter day in Chile!